[mpcrelly]

Hi some of you know that I recently got a rogue atlas magnum amp.  I think she's a keeper for now, but thinking of playing with bias settings.  rogue recommends 35ma.  just wondering what sound changes I should listen for if I got lower or especially higher.  I read that some people don't go much higher than 50ma.  and I have heard that running higher means hotter and shorter tube life.

what sound changes should I listen for??  bass, detail?, distortion (too high?)

thanks!

[Pete Schumacher]

Raising bias will definitely shorten life.  Higher bias will also allow class A operation to higher power levels before it reverts to A/B operation.  Class A operation allows better linearity with lower overall non-linear harmonic content.  That could result in better definition at lower volumes, a purer sound.

If you regularly keep it well below peak output, there's no real advantage to running it hotter.